Operation Inherent Resolve

Operation Inherent Resolve (15 June 2014-present) is the ongoing United States-led aerial campaign by NATO allies and the Gulf States against the Islamic State and other dangerous jihadist groups in Iraq and Syria. The United States intervened as the Islamic State overran much of northern Iraq during the Iraqi Civil War and were closing in on Baghdad and Erbil, and their airstrikes have killed over 30,000 Islamic State fighters and helped in slowing their offensives or coordinating counterattacks on the ground by the Free Syrian Army, Iraqi Army, Peshmerga, or People's Protection Units (YPG) anti-IS forces.

Background
The United States withdrew from Iraq in December 2011 after eight years of fighting against insurgents in the Iraq War, having handed over power to a sectarian government ruled almost exclusively by Shias and Kurds, both of which were oppressed under Saddam Hussein's government from 1979 to 2003. In the aftermath of the withdrawal of US and NATO forces, the Iraqi government was nearly overwhelmed by the insurgents, who grew in numbers due to Prime Minister Haider al-Abadi's poor rule over the country. Former pro-government Sunni Anbar Awakening tribesmen were not allowed to join the new Iraqi security forces, and the jobless Anbar Awakening soldiers either joined the insurgents or suffered due to the lack of money. al-Abadi discriminated against Shi'ites in the government, and the government became dependent on the Shi'ite power of Iran. Iran took Iraq into its sphere of influence, and the Iraqi government was only nominally a United States ally, with its people hating the United States either due to their withdrawal from Iraq and their abandonment of the Iraqi people or because of their occupation of Iraq in the first place. The government of Iraq fought against the insurgents, but in June 2014, the Islamic State of Iraq and Syria militant group launched a massive offensive in northern Iraq, seizing the cities of Mosul, Tikrit, Hit, Ramadi, and half of Kirkuk and threatening Baghdad and the Iraqi government to the south and the government of Iraqi Kurdistan in Erbil to the north. The group persecuted Christians and non-Muslims, and they enforced strict sharia law, using public crucifixions, beheadings, and whippings to intimidate the people under their control, and the group was so violent that even al-Qaeda disavowed its relations with the group. Abu Bakr al-Baghdadi, its leader, proclaimed himself its Caliph, and the group earned the ire of almost every other Islamist group, while some groups like Abu Sayyaf, Jemaah Islamiyah, and Boko Haram and some sections of Vilayat Dagestan and the Taliban pledged allegiance to it. The Islamic State was regarded as a threat by the West as well as the Gulf States, with thousands of foreigners heading to join the group as foreign fighters. With the Islamic State advancing on the city of Erbil, where US diplomatic personnel were stationed, the United States was compelled to intervene against the Islamic State. With the support of the Gulf States and their NATO and non-NATO allies, the United States began a campaign against the Islamic State, named "Operation Inherent Resolve" months later.

History
The United States began their campaign by bombing Islamic State convoys moving towards Erbil, slowing down their advance. Meanwhile, the USA and some European countries began airlifting supplies to besieged Yazidis on Mount Sinjar, where they were besieged by the genocidal Islamic State fighters, who took many Yazidi girls as sex slaves and massacred the men. The US Air Force bombed ISIS positions in Iraq for several months, and in August 2014 the Kurds and Iraqis made their first gain when they recaptured the Mosul Dam from the Islamic State, and the US Air Force was successful in pushing the Islamic State back from Erbil. The Islamic State responded to the bombing by executing American hostages such as James Foley and Steven Sotloff, and their infamous British executioner "Jihadi John" became a media sensation in late 2014 and early 2015 for his executions.

After bombing ISIS forces in Iraq, the United States later expanded its operations to Syria in September 2014 to stop the expansion of the Islamic State in that region, as they had made their capital at ar-Raqqah in Raqqa Governorate in eastern Syria. The Islamic State's cities of ar-Raqqah and Mosul were regularly bombed by the US Air Force, and many ISIS fighters were killed, while civilian casualties were also common. The United States also targeted al-Qaeda and its al-Nusra Front and Khorasan Group affiliates in Syria with their airstrikes, as well as having a few airstrikes against the extremist Ahrar ash-Sham Islamist group. The bombing of Syria was taken as an act of hostility by the Syrian Arab Republic and its ally, Russia, as the United States had not been given permission to bomb the Islamic State by the government, or to use its airspace. In Syria, the Islamic State continued to gain ground into 2015, but in Iraq, the Islamic State was later forced out of the cities of Tikrit, Ramadi, and Sinjar in 2015-2016. Mosul was vulnerable to a ground attack in 2015, but the planned offensive was delayed into 2016. The operation's biggest success was the lifting of the Siege of Kobani in 2014-2015, where the Islamic State besieged Kurdish People's Protection Units forces on the border of Turkey at Kobani. The American bombing killed many ISIS leaders overseeing the siege and helped the Kurds in launching an effective counterattack against the jihadists, and the Islamic State was pushed back several more times. 2015 saw Jihadi John be killed in a US airstrike, the city of Sinjar recaptured and therefore Mosul surrounded, and Kurdish gains in northern Syria with their conquest of Tell Abyad, and the airstrikes paid off. By February 2016, over 30,000 ISIS fighters had been killed.